Everyone starts with 100 shop chests! You may purchase an additional 48 shops to maximize your profit making abilities now or participate in server quests (/quest) and earn them in game.
This will set you at 148 total shops regardless to how many you have received from quests.
IMPORTANT: Check /currency and hover on the Purple Shulker and verify you don't already have the maximum 148 shops.
When gifting someone an item, both users must be online and the purchaser will receive the rank credit.